South Korea will soon have the third largest coalition force in Iraq

South Korean acting president Goh Kun put the country on high alert, saying it was now a major target.

Australia's intelligence chief said that, while the threat at home had not changed, the country's interests overseas could be at risk.

And Interpol's head urged more help from Asian police in fighting terror.

The Madrid attacks are a reminder that these kinds of attacks can occur any day anywhere in the world Ronald Noble Head of Interpol

Ronald Noble told the organisation's regional security conference in the Philippine capital Manila that attacks by al-Qaeda were the "greatest concern and challenge" to the world's police.

"The Madrid attacks are a reminder to the entire world, not just Europe, that these kinds of attacks can occur any day anywhere in the world, and we must try to prepare ourselves the best we can for them," he said.

In separate developments in the region:

• Japan is considering tightening security around its railway network
• Philippine President Gloria Arroyo pledges to keep troops in Iraq, saying that terrorists are unlikely to limit their attacks to allies of the US
• New Zealand's government denies a charge by the country's intelligence chief that the country is being used by terrorists as a place to lie low, and says there is no significant security threat to the country.

In the wake of the attacks, South Korean leaders convened a meeting of the government's anti-terror committee to decide new security measures.

Goh Kun called for additional measures to prevent attacks on public facilities, and for thorough preparations to ensure the safety of troops being sent to Iraq.

South Korea currently has 465 military medics in Iraq.

It is sending another 3,000 troops in April, to take control of security and reconstruction around the northern city of Kirkuk.

This contingent will make the South Korean force the third largest in Iraq after the US and the UK.

The al-Qaeda network has said it will target countries which have sent troops to Iraq.

Expenditure boost

The government of Australia, which has around 300 troops in Iraq, has rejected claims that its support for the US-led coalition raised the threat from al-Qaeda.

But Dennis Richardson, the director-general of the Australian Security Intelligence Organisation, said there could be a threat to Australians in areas like the Middle East.

"The overall threat level in respect of Australia has not changed," he said. "But the threat levels in respect of some Australian interests overseas ... have changed because of Iraq."

The remarks came as Prime Minister John Howard announced that an extra $300m for the intelligence services would be included in the May budget.

He said the additional money meant Australia had boosted expenditure on security by $3bn since the 11September 2001 attacks on the US, adding that the latest increase had been decided before the Madrid bombings.

Meanwhile Attorney-General Philip Ruddock announced a major anti-terrorism exercise next week to test the country's readiness to cope with chemical, biological and radiological attacks.

Mr Ruddock also announced plans to make it illegal for Australians to fight for terrorist organisations or enemy armies.